Solar Tracker

ABSTRACT

A free-standing solar tracker comprises a base, a support frame, a panel assembly comprising one or more solar panels, and an actuator to rotate the panel assembly to track the movement of the sun. The solar tracker is designed to be free-standing and requires no foundation. When the solar tracker is deployed, the base forms a pan to contain a ballast material for holding the base in place. The base of the solar tracker is designed to serve as a “suitcase” to contain most of the components of the solar tracker, making it easier to transport the solar tracker  10  to a location where the solar tracker is installed.

BACKGROUND

The present invention relates generally to solar panels for generatingsolar energy and, more particularly, to a free-standing solar trackerwith a rotating panel assembly to track the movement of the sun duringthe day.

Photovoltaic panels, or solar panels, have been used for a long time incommercial and residential applications. A solar panel typicallycomprises a plurality of photovoltaic cells, also known as solar cells,that convert sunlight into electricity. In most commercial orresidential applications, a large array of solar panels is needed togenerate enough energy to have any practical effect. Thus, the use ofsolar panels requires a relatively large amount of open space exposed todirect sunlight. Most often, solar panels are mounted on the roofs ofhomes and buildings. In most installations, the solar panels are mountedin a fixed position to maximize the exposure when the sun is at itspeak.

Conventional solar systems have not gained widespread acceptance for anumber of reasons, including the cost of the solar systems, theavailability of adequate space, and aesthetic reasons. Conventionalsolar systems typically cost more than other available energy sources.The added expense of solar systems is an impediment to adoption of solarsystems. Also, many people who are willing to pay the extra cost of asolar system may not be able to do so because they lack adequate spaceexposed to the sun. Others may consider solar panels mounted on theroofs of homes to be aesthetically unappealing. Concerns over theaesthetics of the solar panels are another impediment to adoption ofsolar systems.

Therefore, there is a continuing need for a solar system that isrelatively inexpensive, that can be deployed in a relatively small area,and overcome concerns regarding aesthetics of the solar panels.

SUMMARY

The present invention provides a free-standing solar tracker that can beused for both residential and commercial applications. The solar trackercomprises a base, a support frame, a panel assembly including one ormore solar panels, and an actuator to rotate the solar panel to trackthe movement of the sun. The solar tracker is designed to befree-standing and requires no foundation. When the solar tracker isdeployed, the base forms a pan to contain a ballast material for holdingthe base in place. Thus, the solar tracker can be easily moved to a sitewith adequate exposure to the sun.

The solar tracker is designed to be relatively inexpensive to build andoperate. Additionally, the ability to track the movement of the sunsignificantly increases the output of the solar panel assembly, thusincreasing the user's return on the investment in the solar system. Thefree-standing support enables the solar tracker to be deployed in anylocation with adequate exposure. Also, the ability to deploy the solartracker in any desired location means that the solar tracker can bedeployed in locations that will not detract from the appearance of theowner's home or building.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective views of a solar tracker according to a firstexemplary embodiment of the invention with its solar panel in a firstrotational position.

FIG. 2 is perspective views of a solar tracker according to the firstexemplary embodiment of the invention with its solar panel in a secondrotational position.

FIG. 3 is a front elevation of the solar tracker.

FIG. 4 is a side elevation of the solar tracker.

FIGS. 5 and 6 illustrate the mounting of the panel assembly to thesupport frame.

FIG. 7 illustrates the actuator assembly and mounting of the panelassembly to the support frame.

FIG. 8 illustrates the base of the solar tracker with disassembledcomponents of a support frame and panel assembly stored inside the base.

FIG. 9 illustrates the base of the solar tracker closed to contain thedisassembled components of a support frame and panel assembly.

FIG. 10 illustrates a second embodiment of the solar tracker.

FIG. 11 illustrates a third embodiment of the solar tracker.

DETAILED DESCRIPTION

Referring now to the drawings, a solar tracker 10 according to thepresent invention is shown. The solar tracker 10 generally comprises abase 20, support frame 40, panel assembly 60, and actuator assembly 90for rotating the panel assembly 60 to follow the azimuth of the sun asit moves across the sky. The solar tracker 10 is designed to befree-standing and requires no foundation. Thus, the solar tracker 10 canbe easily moved between sites. The base 20 of the solar tracker isdesigned to serve as a “suitcase” to contain most of the components ofthe solar tracker 10, making it easier to transport the solar tracker 10to a location where the solar tracker is installed.

The base 12 of the solar tracker 10 is formed in two sections 22 thatare connected to one another by a hinge 24. The base sections 22 aremovable between an open or deployed position (FIGS. 1-5) and a closed orstorage position (FIG. 56). Each section 22 comprises a pair of sidemembers 26 and a pair of end members 28 forming a generally-rectangularframe. The side members and end members may be constructed of a metaltubing, metal channel, or metal beam. A bottom sheet 30 made of a sheetmetal is fixedly attached to the frame such as by welding to form anopen pan in the deployed position. Separators 32 are spacedlongitudinally between the end members 28 and extend between the sidemembers 26. The separators 32 may be inserted into tracks or channels(not shown) in the side members 26 so that the separators can beremoved. In a preferred embodiment, the separators 32 are formed of asheet metal and extend approximately two-thirds the height of the sidemembers 26. The separators 32 prevent the ballast material from shiftingand help maintain the ballast material evenly distributed over the panformed by the base 20. In use, the base sections 22 are unfolded so thatthey lie side-by-side. The base sections 22 can then be bolted togetherin the open position or may be held together by the hinge 24.

The support frame 40 mounts to the base 20. The support frame 40comprises front frame 42 and a rear frame 52. The front frame 42comprises a pair of legs 44, a gusset plate 46, and a strut 50, whichmay be made of metal and removably connected together by bolts and nuts,or other suitable fasteners. The legs 44 may be made of rigid material,such as a metal angle. The legs 44 extend upwardly at an angle from theone end of the base 20. The lower ends of the legs 44 are bolted orotherwise secured to respective end members 28 of the base 20. The upperend of the legs 44 are connected by a gusset plate 46, which may be madeof a metal plate. The gusset plate 46 provides rigidity to the frame 42,as well as provides a surface for mounting the panel assembly 60 ashereinafter described. Strut 50 is made of a rigid material, such as ametal angle, and provides lateral stability for the front frame 42. Thestrut 50 is connected at the lower end to the side members 26 of thebase 20, and at the upper end to the gusset plate 46 of the frame 42.

The rear frame 50 includes a pair of legs 52, gusset plate 52, and strut56, which may be made of metal and removably connected together by boltsand nuts, or other suitable fasteners. The legs 52 extend upwardly at anangle from respective end members 28 of the base 20. The lower ends ofthe legs 52 are bolted or otherwise secured to the end members 28, whilethe upper ends of the legs 52 are connected by the gusset plate 54,which may be made of a metal plate. Strut 56 extends between the base 20and gusset plate 54 to provide lateral stability to the rear frame 52.It may be noted that the rear frame 50 is tilted at a slight anglerelative to the base 20, whereas the front frame 42 is perpendicular tothe base 20. The exact orientation of the frames 42, 50, however, is notmaterial. Depending on the size of the frame 42, reinforcing members 58may be provided to interconnect the legs 52 at spaced locations.

The panel assembly 60 comprises a plurality of solar panels 62 and apanel support frame 64 to support the solar panels. The panel supportframe 64 comprises a central spine 66, a pair of laterally-spaced sidemembers 68, and a plurality of longitudinally-spaced panel carriers 70,which can be removably connected by bolts and nuts, or other fasteners.The panel carriers 80 include an inner end and an outer end. The innerend connects to the spine 66 and while the side member 78 connect to theouter ends of the panel carriers 70. The spine 66 in the exemplaryembodiment is made from a metal tube, while the side members 68 andpanel carriers are made of a metal channel. The panel carriers 70 taperfrom the inner end to the outer end. The side members 68 are spaced fromthe spine 66 so that the inner ends of the solar panels rest on a topsurface of the spine 66, while the outer ends of the solar panels reston a top surface of the side members 68. The panel carriers 70 arelongitudinally-spaced so that the side edges of the solar panels 62 reston the top surfaces of respective wing member 70. The solar panel 62 canbe removably secured to the panel support frame 64 by bolts, screws,clamps, or other mechanical fastening devices.

The panel assembly 60 is rotatably mounted to the support frame 40 so asto rotate about a single, inclined axis. FIG. 5 shows a first mountingassembly 80 for securing the lower end of the panel assembly 60 to thefront support frame 42. The first mounting assembly 80 comprises aconnecting plate 82, L-shaped mounting brackets 84, bearing 86, and apivot member 88. The connecting plate 82 is bolted, welded, or otherwisesecured to the gusset plate 46 of the front frame 42. The connectingplate 82 is bent at a slight angle to provide the desired tilt for therotational axis of the panel assembly 60. Mounting brackets 84 arebolted or welded to the spine 66 of the panel support frame 64. Theupper end of connecting plate 82 and bearing 66 are disposed between thebrackets 86. Pivot member 88, such as a bolt, passes through themounting brackets 84, connecting plate 82, and bearing 86, and issecured by a conventional nut threaded onto the end of the pivot member88.

FIGS. 6 and 7 shows a second mounting assembly 90 for mounting the upperend of the panel support frame 64 to the rear support frame 50. Thesecond mounting assembly 90 comprises a connecting plate 92, a pair ofmounting forks 94, a bearing 96, and a pivot member 98. Connecting plate92 is secured by bolts or other mechanical fasteners to the gusset plate56 of the rear support frame 50. The mounting forks 94 include a slot 95to receive the spine 66 of the panel support frame 64. The mountingforks 94 may be permanently fixed to the spine 66 by welding. Bearing 96is disposed between the lower end of the mounting forks 94. Pivot member98 extends through the mounting forks 94, upper end of connecting plate92, and bearing 96, and is secured in place by a nut threaded onto theend of the pivot member 98.

Pivot member 88 on the first mounting assembly 80 and pivot member 98 onthe second mounting assembly 90 are co-axially aligned along the axisand rotation of the panel assembly 60. The rotational axis inclinesupwardly from front to rear in a plane perpendicular to the base 20. Therotational axis is aligned when deployed so that the plane of therotational axis aligns with the sun at the highest altitude. Thus, thepanel assembly 60 can rotate to track the path of the sun as the suntravels across the sky during the day.

Actuator assembly 100, shown in FIG. 7, comprises a pivot arm 102, fluidcylinder 102, and control unit 106. Pivot arm 102 is connected at oneend to the spine 66 of the panel support frame 64. Pivot arm 102 extendsoutward from the spine 66. Fluid cylinder 104 is connected at one end tothe pivot arm 102 and the opposite end to the front Frame. Control unit106 is mounted to the front Frame and controls operation of the fluidcylinder 104. The extension of the fluid cylinder 104 rotates the panelassembly 60 in a first direction, while retraction of the fluid cylinder104 rotates the panel assembly 60 in the opposite direction. The controlunit 106 preferably includes a processor and associated memory forcontrolling the rotation of the panel assembly 60. The control unit 106may store ephemeras data in memory that gives the position of the sun inthe sky at different times of the day. Alternatively, the position ofthe sun in the sky at different times of day may be calculated based onformulas that model the sun's movement. As the azimuth of the sunchanges, the control unit 106 rotates the panel assembly 60 to minimizeas much as possible the angle of incidence of the sun rays on the solarpanels 62. It is noted that the panel assembly 60 rotates about a singleaxis that follows the azimuth of the sun. Those skilled in the art willappreciate that it is also possible to change the angle of inclinationof the solar panels to track changes in the altitude of the sun.

As previously noted, the solar tracker 10 is designed so that most ofthe components can be disassembled and packaged in the base 20. FIG. 8shows the base 20 with the base sections 22 folded open. FIG. 9 showsthe panel carriers 70 stored in one of the base sections 22. Componentsof the support frame 40 may, likewise, be disposed in one of the basesections. Essentially all of the components, with the exception of thespine 66 and solar panels 62, will fit inside the base sections 22. Thebase sections 22 can then be folded to a closed position as shown inFIG. 9 to form a suitcase with a compartment containing most of thesolar tracker components.

FIG. 10 shows a second embodiment of the solar tracker. This embodimentis the same as the first embodiment except for the construction of thebase, which is designated by reference number 120 in this embodiment.The base 120 comprises an I-shaped frame having center beam 122 and apair of end beam 124. The end beams 124 may be secured to the centerbeam 122 by bolting, welding, or other suitable means. In theillustrated embodiment, the center beam 122 and end beams are metalI-beams. Those skilled in the art will appreciate that the center beam122 and end beams 124 may also comprise metal channels, metal tubes, orother structural members.

The base 120 is designed to lie on a flat surface. The base 120 is heldin place by specially-designed ballast containers 130 that contain aballast material, such as sand, gravel, water, etc. In the exemplaryembodiment shown in FIG. 6, the ballast containers 130 comprise opencontainers having a bottom 132, side walls 134, and open top 136. Achannel 138 is formed in the bottom 132 of the ballast containers 130 sothat the center beam 122 of the base 120 can pass through the ballastcontainers 130 as shown in FIG. 10. Thus, the ballast containers 130effectively straddle the center beam 122 of the base 120. Once theballast containers 130 are placed on the center beam 122 as shown inFIG. 100, the ballast containers 130 can be filled with a ballastmaterial (e.g., gravel, sand, water, etc) to hold the base 120 in place.

While the embodiment shown in FIG. 6 contains the ballast material inopen ballast containers 130, those skilled in the art will appreciatethat closed ballast containers 130 could also be used. For example, theballast container 130 may comprise a closed container with a fill holefor filling the ballast container 130 with water or other fluid. Theballast container 130 could be formed with handle or other features forcarrying the ballast containers 130. The ballast containers 130 may alsohave features for stacking and/or nesting the ballast containers 130.

FIG. 11 shows a third embodiment of the solar tracker. Like, theprevious embodiment the base 120 comprises an I-shaped frame havingcenter beam 122 and a pair of end beam 124. The end beams 124 may besecured to the center beam 122 by bolting, welding, or other suitablemeans. In the illustrated embodiment, the center beam 122 and end beamsare metal tubes. Those skilled in the art will appreciate that thecenter beam 122 and end beams 124 may also comprise metal channels,metal I-beams, or other structural members.

The base 120 is designed to lie on a flat surface. The base 120 is heldin place by anchor members 140 that are embedded in the ground or othersupport surface. Anchor brackets 142 connect the anchor members to theend beams 124 of the base 120.

The present invention provides a free-standing solar tracker 10 that canbe easily transported to a desired location and installed. The solartracker assembly 10 is designed to be free-standing and does not requireany foundation. The solar tracker 10 rests on the surface of the groundand is held in place by ballast material. If desired, the solar trackerassembly 10 may be placed on a concrete pad, but there is no need inmost instances to fasten the solar tracker to the concrete pad. However,those skilled in the art will appreciate that tie-down straps or othersecuring devices could be used in conjunction with the ballast material,particularly where very high winds are expected. The base of the solartracker assembly is designed to serve as a “suitcase” for transportingthe components of the solar tracker 10. As noted previously, most of thecomponents of the solar tracker, with the exception of the spine 66 andsolar panels 72, can be packaged within the base 20 for transportationand storage.

The present invention may, of course, be carried out in other specificways than those herein set forth without departing from the scope andessential characteristics of the invention. The present embodiments are,therefore, to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

1. A solar tracker comprising: a base forming an open pan for containinga ballast material; a support frame mounted to said base; a panelassembly rotatably mounted to said support frame, said panel assemblyincluding a plurality of solar panels; and an actuator assembly forrotating the panel assembly to track the movement of the sun.
 2. Thesolar tracker of claim 1 wherein said base comprises first and secondsections that are movable between a storage position and deployedposition, wherein the base forms said open pan in the deployed positionfor holding the ballast material and forms a carrier in the storageposition including a closed compartment for containing disassembledcomponents of the support frame and panel assembly.
 3. The solar trackerof claim 2 wherein the panel assembly comprises: a central spinerotatably mounted to the support frame; and a plurality of panelcarriers extending outwardly from said spine for supporting said solarpanels.
 4. The solar tracker of claim 3 wherein panel carriers areremovably connected to the spine and are configured to fit inside saidclosed compartment when said base is in the storage position.
 5. Thesolar tracker assembly of claim 3 including a mounting assembly forrotatably mounting the panel assembly to the support frame, saidmounting assembly comprising: a mounting fork configured to be pivotallyconnected to said support frame; and a slot in said mounting forkconfigured to receive the spine of the panel assembly.
 6. The solartracker assembly of claim 2 wherein the support frame includes twospaced end frames configured to be removably connected at respectiveends of the base when the base is in the deployed position.
 7. The solartracker of claim 6 wherein the support frame includes two or more framemembers that can be disassembled and placed inside said compartment ofsaid base when said base is in the storage position.
 8. The solartracker of claim 1 wherein the panel assembly is mounted to rotate aboutan inclined rotational axis lying in a plane perpendicular to the basesuch that the rotation of the panel assembly tracks changes in theazimuth of the sun.
 9. A solar system comprising: a base having firstand second section configurable in a deployed position and a storageposition, said base forming an open pan for containing a ballastmaterial in the deployed position and forming a carrier having aninternal compartment ion the storage position; a support frame removablymounted to said base, said support frame including one or more framemembers configured to be contained in the internal compartment of thebase when the base is configured in a storage position; and a panelassembly removably mounted to said support frame, said panel assemblyincluding an array of solar panels.
 10. The solar system of claim 9wherein the panel assembly comprises a central spine rotatably mountedto the support frame; and a plurality of panel carriers extendingoutwardly from said spine for supporting said solar panels.
 11. Thesolar system of claim 10 wherein panel carriers are removably connectedto the spine and are configured to fit inside said internal compartmentof said base when said base is in the storage position.
 12. A solarsystem comprising: a base comprising one or more base beams that rest onan underlying support surface; a support frame mounted to said base; apanel assembly mounted to said support frame, said panel assemblyincluding a plurality of solar panels; and one or more ballastcontainers configured to straddle at least one of the base beams forcontaining a ballast material to hold said solar tracker in place. 13.The solar system of claim 12 said panel assembly is rotatably mounted tosaid frame and further comprising an actuator assembly for rotating thepanel assembly to track the movement of the sun.
 14. The solar trackerof claim 13 wherein the panel assembly comprises a central spinerotatably mounted to the support frame; and a plurality of panelcarriers extending outwardly from said spine for supporting said solarpanels.
 15. The solar tracker assembly of claim 14 including a mountingassembly for rotatably mounting the panel assembly to the support frame,said mounting assembly comprising: a mounting fork configured to bepivotally connected to said support frame; and a slot in said mountingfork configured to receive the spine of the panel assembly.
 16. Thesolar tracker assembly of claim 15 wherein the support frame includestwo spaced end frames configured to be removably connected at respectiveends of the base when the base is in the deployed position.
 17. Thesolar tracker of claim 12 wherein the panel assembly is mounted torotate about an inclined rotational axis lying in a plane perpendicularto the base such that the rotation of the panel assembly tracks changesin the azimuth of the sun.